This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. 119 from an application for APPARATUS FOR DETERMINING CARTRIDGE TYPE IN THE PRINTER FOR MICRO INJECTING DEVICE earlier filed in the Korean Industrial Property Office on Sep. 13th 1999 and there duly assigned Ser. No. 38927/1999.
1. Field of the Invention
The present invention relates to an apparatus for determining the cartridge type of a printer, and more particularly, to an apparatus for determining the cartridge type of the printer using a micro injecting device.
2. Description of the Related Art
In general, a micro injecting device applies electric energy or heat energy to a small amount of a fluid, such as ink, an injectable solution, or gasoline; the application of energy causes a volume change so that the fluid is supplied to a desired location, such as a sheet of printing paper or to a vehicle. Inkjet printers are illustrative of such applications.
An inkjet printer using a micro injecting device is capable of embodying various colors according to selection of a cartridge, unlike a conventional dot matrix printer; it also has a reduced noise and an excellent print quality.
An inkjet printer generally includes a printer head having a nozzle of minute diameter. Such a printer head converts ink from a liquid state to a vapor state by application of an electric signal. After that, the inkjet printer squirts the ink to the outside to cause a printing operation to be performed.
In a typical inkjet printer, because the printer head is integrated with the ink cartridge, a user must replace an entire printer head assembly, in which the ink cartridge and the printer head are integrated together, when ink is exhausted.
Such an inkjet printer is designed to selectively replace various types of cartridge, such as a mono cartridge, a color cartridge, or a photo cartridge. To obtain optimum print quality, it is preferable to determine the type of cartridge used and then perform control suitable for the corresponding cartridge.
Conventionally, to determine cartridge type, a nonvolatile RAM (NVRAM), in which information as to the cartridge type is recorded, is mounted inside the cartridge. When the cartridge is mounted or a system is initialized, a central processing unit inside the inkjet printer detects information recorded in the NVRAM to determine information about the cartridge.
However, the conventional method for determining cartridge type has several problems. First, if the NVRAM is mounted in a disposable cartridge and the information about the cartridge is recorded in the NVRAM, the manufacturing cost of the cartridge rises, thereby imposing economic burden on consumers. Moreover, if the cartridge gets a shock, the NVRAM may get out of order, and then the cartridge type may not be determined correctly.
It is, therefore, an object of the present invention to provide an apparatus for determining the cartridge type of a printer using a micro injecting device. The apparatus detects a contact-state sensing signal of a dimple part, which is a power cable connection part for a cartridge. It is detected according to its contact structure being different depending on the type of cartridge, and a cable, thereby determining the cartridge type.
It is another object of the present invention to provide an apparatus for determining the cartridge type of a printer using a micro injecting device. The detection apparatus detects resistances having different resistance values and voltage divided by reference resistor value inside a central processing unit to determine type of the corresponding cartridge.
According to the present invention, the apparatus for determining the cartridge type of the printer using a micro injecting device comprises: a connection means having at least two or more cartridge type sensing contact parts, the connection means being electrically connected to each cartridge having a different contact structure dependent on the type of cartridge, and outputting different contact signals depending on the type of cartridge; and a central processing unit detecting a contact signal transmitted from the connection means, comparing the detected contact signal with a preset standard contact signal and thereby determining cartridge type.
The connection means includes a number of dimple parts corresponding to the contact parts of the cartridge and is electrically connected with the cartridge. Moreover, one of the contact parts of the cartridge is electrically connected with at least one of the remaining contact parts.
According to the present invention, the central processing unit comprises: a constant voltage regulated power supply electrically connected to one of the contact parts for sensing the cartridge type to supply preset constant voltage; a pull-up resistance connected between the constant voltage regulated power supply and one of the contact parts; and one or more contact signal input terminals electrically connected to the remaining contact parts, besides the contact part connected to the pull-up resistance, in one-to-one manner, wherein the central processing unit detects that power source provided by the constant voltage regulated power supply is supplied to at least one or more contact signal input terminals through the pull-up resistance corresponding to the contact structure of the cartridge, and determines cartridge type according to the detected signal of the contact signal input terminals.
The cartridges are divided into a mono cartridge of a single color, a color cartridge having two or more colors, and a photo cartridge.
Additionally, the printer according to the present invention comprises: a central processing unit having a constant voltage regulated power supply for supplying a preset constant voltage and a reference resistor connected to the constant voltage regulated power supply, the reference resistor having a preset resistance value; and connection means connected to the cartridge, which has a partial resistance having a different resistance value depending on the type of cartridge and an earth (ground) terminal connected to the partial resistance, the connection means electrically connecting the partial resistance of the cartridge and the reference resistor of the central processing unit in series, wherein when the cartridge and the central processing unit are electrically connected, the central processing unit detects the level of the partial voltage, which is supplied from the constant voltage regulated power supply, divided by the partial resistance of the cartridge and the reference resistance of the central processing unit, compares a level of the detected partial voltage with at least one preset reference level value and determines cartridge type according to the compared result.
According to the present invention, the central processing unit further includes an analog/digital converter for digitizing the partial reference divided by the partial reference of the cartridge and the reference resistance of the central processing unit.